Detect method and the pick-up unit of PVA film gas-premeable
Technical field
The present invention relates to detection field, particularly a kind ofly can be used for the method and apparatus detecting PVA film gas-premeable, the method can efficiently and accurately for detecting PVA film gas-premeable.
Background technology
PVA (polyvinyl alcohol (PVA)) is the main material forming polaroid, by PVA polymer film is passed through orientation stretching, make iodine or the arrangement of organic dye molecular orientation of the inside, thus obtain the performance of polarisation, namely obtain PVA polaroid, be applied to comparatively widely in the optics such as liquid crystal display, sunglasses, 3D glasses and electronic product.
PVA film due to purposes comparatively extensive and special, especially in optics and electronic product, under the condition meeting optical property, optical grade PVA film also needs to meet certain index in pulling strengrth, breaking elongation, water vapor transmittance and wet-hot aging performance etc., to carry out machining and to reach longer serviceable life; In prior art, PVA film all needs to do steam breathability detection before for product; Steam breathability is detected and is generally detected by special water vapor transmittance detecting instrument.Water vapor transmittance detecting instrument due to complex structure price costly, and in use procedure safeguard and maintenance cost higher; Time required during detection is longer, generally needs the sense cycle of 1-2 days, is not suitable for the detection of product batch production; Owing to being directly detect film, the outward appearance of film and some uniform defects (gas point, chap) can be comparatively large to film whole detection Influence on test result, have certain error or deviation.
Therefore need a kind of method for detecting PVA film gas-premeable, the course of work is simple and the cycle is shorter, is applicable to the detection of product batch production, the lower water of equipment making, maintenance and maintenance cost; Further, do not need directly to detect film forming, the defect of film itself (gas point, chap) can not impact film whole detection result, and result accuracy is higher.
Summary of the invention
In view of this, the object of the present invention is to provide a kind of method and the pick-up unit that detect PVA film gas-premeable, the course of work is simple and the cycle is shorter, is applicable to the detection of product batch production, the lower water of equipment making, maintenance and maintenance cost; Further, do not need directly to detect film forming, the defect of film itself (gas point, chap) can not impact film whole detection result, and result accuracy is higher.
The method of detection PVA film gas-premeable of the present invention, comprises the following steps:
A. oxygen is passed in pure water the aqueous solution forming certain volume percentage oxygen;
B. utilize the aqueous solution of step a to form electrode system, the working electrode I in electrode system is dipped the PVA solution for the formation of PVA film, after drying, form PVA film on working electrode I surface;
C. be energized and record PVA film cover after the response voltage of working electrode I in the aqueous solution of the certain volume percentage oxygen of step a;
D. record the response voltage of the working electrode II in electrode system in the aqueous solution of the certain volume percentage oxygen of step a, described working electrode II is bare electrode;
E. contrast the response voltage in step c neutralization procedure d, obtain oxygen transfers to working electrode I relative velocity by PVA film.
Further, in step a, oxygen is passed in pure water the multiple aqueous solution forming different volumes percentage oxygen; In step c, be energized and record PVA film cover after the response voltage of working electrode I in the multiple aqueous solution of the different volumes percentage oxygen of step a; In steps d, record the response voltage of the working electrode II in electrode system in the multiple aqueous solution of the different volumes percentage oxygen of step a;
Further, in step a, at standard conditions, high pure nitrogen and oxygen to be passed into respectively in pure water at least 20min, and setting to pass into oxygen purity in the aqueous solution of nitrogen be 0%, it is 100% that setting passes into oxygen purity in the aqueous solution of oxygen, two kinds of solution is pressed different proportion mixing, obtains the aqueous solution of different Relative volume fraction oxygen;
Further, in step a, nitrogen and oxygen two kinds of solution are mixed according to the ratio of volume ratio 1:4,2:3,3:2 and 4:1, the oxygen content in the solution obtained is set as 80%, 60%, 40% and 20% respectively; In step c and steps d, record respectively working electrode I and working electrode II oxygen percent by volume be 80%, 60%, 40% and 20% response voltage.
The invention also discloses a kind of pick-up unit of the method for detecting PVA film gas-premeable, comprising electrode system and providing power supply and the workstation that its data are processed for electrode system; Described electrode system comprises working electrode I, working electrode II and to electrode, described working electrode I and working electrode II are equipped with contrast electrode, described working electrode I is for dipping PVA solution and forming PVA film at its working surface, and described working electrode II is bare electrode.
Further, the contrast electrode of described working electrode I and working electrode II is hollow edged electrode, described working electrode I and working electrode II through respective contrast electrode and with its insulation, the front end of working electrode I and the front end of working electrode II pass respective contrast electrode and form active section, and rear end is by respective wire electrical connection workstation;
Further, described working electrode I and working electrode II are electrically connected on workstation by the skin of respective concentric bilayer wire, and the internal layer of concentric bilayer wire is electrically connected on contrast electrode;
Further, electrical connection place of described working electrode I and working electrode II and respective contrast electrode and working electrode I and working electrode II and respective wire encapsulates and forms one; Or at least working electrode I and working electrode II carry out hermetically sealed with the front end of respective contrast electrode;
Further, the contrast electrode that described working electrode I is corresponding different respectively with working electrode II; Or working electrode I and working electrode II are all positioned at same contrast electrode;
Further, the described workstation voltage response signal comprised for receiving working electrode I and working electrode II is gone forward side by side row relax and export the department of computer science of comparing result and unify for electrode system provides the power circuit of power supply.
Beneficial effect of the present invention: the method for detection PVA film gas-premeable of the present invention and pick-up unit, utilize the oxygen in electrode system measurement pure water by PVA film principle and obtain response voltage, obtain the speed that oxygen passes through PVA film with contrast under the condition of normal (not having PVA film) to convert, thus obtain PVA film gas-premeable, the whole course of work is simple and the cycle is shorter, response time is fast, detect and only need 1-2 hour, be applicable to the detection of product batch production, equipment adopts existing electrode system principle, and method according to the present invention makes, make, safeguard and the lower water of maintenance cost, further, utilize working electrode directly to dip solution and drying and forming-film, do not need directly to detect film forming, the defect of film itself (gas point, chap) can not impact film whole detection result, and result accuracy is higher.
Accompanying drawing explanation
Below in conjunction with accompanying drawing, the present invention is further described;
Fig. 1 is structure of the detecting device schematic diagram of the present invention;
Fig. 2 is the voltage responsive figure of working electrode I;
Fig. 3 is the voltage responsive figure of working electrode II;
Fig. 4 is the voltage responsive calibration curve comparison diagram of working electrode I and working electrode II.
Embodiment
The voltage responsive figure of Fig. 2 to be the voltage responsive figure of working electrode I, Fig. 3 be working electrode II, Fig. 4 is the voltage responsive calibration curve comparison diagram of working electrode I and working electrode II, and the method for the detection PVA film gas-premeable of the present embodiment, comprises the following steps:
A. oxygen is passed into the aqueous solution forming certain volume percentage oxygen in pure water (deionized water); Percent by volume herein can be calculate the absolute percent by volume obtained, and also can be the relative percent by volume setting acquisition by calculating;
B. the aqueous solution of step a is utilized to form electrode system, working electrode I 1 (drying) in electrode system is dipped the PVA solution for the formation of PVA film, PVA film is formed on working electrode I 1 surface after drying, the position dipped should be the active section of working electrode I 1, active section refers to the part immersing solution conductivity, does not repeat them here; Electrode system generally comprises working electrode, contrast electrode and to electrode, does not repeat them here;
C. be energized and record PVA film cover after the response voltage of working electrode I 1 in the aqueous solution of the certain volume percentage oxygen of step a;
D. record working electrode II (structure of working electrode II is identical with working electrode I, does not have to represent in the figure) response voltage in the aqueous solution of the different volumes percentage oxygen of step a in electrode system, described working electrode II is bare electrode; Utilize the response voltage difference in step c and steps d, convert and obtain the transfer rate of oxygen, thus obtain gas penetration potential parameter;
E. contrast the response voltage in step c neutralization procedure d, obtain oxygen transfers to working electrode I 1 relative velocity by PVA film; By the response voltage in contrast step c neutralization procedure d, transferred to the relative velocity of working electrode I 1 by PVA film by calculating acquisition oxygen, whole computation process obtains by computer calculate.
Specifically see shown in Fig. 2,3 and 4, by measuring and contrasting, obtain the transmission speed of the oxygen of the working electrode I 1 with PVA film.
In the present embodiment, in step a, oxygen is passed in pure water the multiple aqueous solution forming different volumes percentage oxygen; In step c, be energized and record PVA film cover after the response voltage of working electrode I 1 in the multiple aqueous solution of the different volumes percentage oxygen of step a; In steps d, record the response voltage of the working electrode II in electrode system in the multiple aqueous solution of the different volumes percentage oxygen of step a;
In the present embodiment, in step a, at standard conditions, high pure nitrogen and oxygen to be passed into respectively in pure water at least 20min, and setting to pass into oxygen purity in the aqueous solution of nitrogen be 0%, it is 100% that setting passes into oxygen purity in the aqueous solution of oxygen, two kinds of solution is pressed different proportion mixing, obtains the aqueous solution of different Relative volume fraction oxygen; Obtain the oxygen percent by volume relative with inert gas (nitrogen) by the mode of setting, and utilize the aqueous solution of different percent by volume oxygen, obtain comparatively intuitively with gas penetration potential parameter accurately.
In the present embodiment, in step a, nitrogen and oxygen two kinds of solution are mixed according to the ratio of volume ratio 1:4,2:3,3:2 and 4:1, the oxygen content in the solution obtained is set as 80%, 60%, 40% and 20% respectively; In step c and steps d, record respectively working electrode I and working electrode II oxygen percent by volume be 80%, 60%, 40% and 20% response voltage.
Fig. 1 is structure of the detecting device schematic diagram of the present invention, the pick-up unit of the method for detecting PVA film gas-premeable of the present embodiment, comprise electrode system and provide power supply and the workstation that its data are processed for electrode system, workstation generally comprises the power supply providing voltage, carries out data processing and can adopt existing computer system and can realize in conjunction with specific software; Data herein refer to the voltage response data, difference data etc. that electrode system obtains; Described electrode system comprises working electrode I 1, (working electrode II is identical with working electrode I for working electrode II, do not represent separately in Fig. 1) and to electrode (generally adopting platinum electrode), described working electrode I 1 and working electrode II are equipped with contrast electrode 3, described working electrode I 1 is for dipping PVA solution and forming PVA film at its working surface, and described working electrode II is bare electrode; Working electrode I 1, working electrode II adopt gold at the present embodiment, and contrast electrode can be that working electrode I 1 and working electrode II share, and also can be set up separately separately, not repeat them here.
In the present embodiment, the contrast electrode 3 of described working electrode I 1 and working electrode II is hollow edged electrode, described working electrode I 1 and working electrode II through respective contrast electrode 3 and with its insulation, working electrode I 1 and working electrode II can adopt enameled wire structure, and are formed between contrast electrode 3 and insulate; The front end of working electrode I 1 and the front end of working electrode II pass respective contrast electrode and form active section, active section refer to for part electrode being formed to electrode system; Rear end is by respective wire electrical connection workstation; The structure of electrode system generally comprises working electrode, contrast electrode and to electrode, working electrode, contrast electrode and be all electrically connected on power supply and control circuit to electrode, again repeats no more.
In the present embodiment, described working electrode I 1 and working electrode II are electrically connected on workstation by the skin 6 of respective concentric bilayer wire, the internal layer 6 of concentric bilayer wire is electrically connected on contrast electrode 3, adopts the structure of concentric conductor, makes structure of the present invention compact and simple further.
In the present embodiment, electrical connection place of described working electrode I 1 and working electrode II and respective contrast electrode 3 and working electrode I 1 and working electrode II and respective wire encapsulates and forms one; Packaged type can adopt the tubular structure 4 of an integral plastics material, is positioned in tubular structure by above-mentioned parts, is encapsulated by epoxy resin 2, waterproof and dampproof, and avoids damaging, easy to use; In this structure, working electrode I can be adopted to be packaged into one with its contrast electrode and working electrode I 1 with the junction of its wire, and working electrode II is packaged into one with its contrast electrode and working electrode II with the junction of its wire; Also can be working electrode I 1, the junction of working electrode II contrast electrode 3 respective with it and working electrode I 1, working electrode II wire respective with it is packaged into one jointly; All goal of the invention can be realized; Certainly, also can be that at least working electrode I and working electrode II carry out hermetically sealed with the front end of respective contrast electrode, all can realize goal of the invention.
In the present embodiment, the contrast electrode 3 that described working electrode I 1 is corresponding different respectively with working electrode II, namely working electrode I 1 and working electrode II can separately encapsulate and independent cut-in operation station, use comparatively flexible.
Certainly, working electrode I 1 and working electrode II also can be adopted all to be positioned at the structure of same contrast electrode, certainly to need mutual insulating and adopt different wires, but do not affect whole parts be packaged into one, structure is more simply compact.
In the present embodiment, the described workstation voltage response signal comprised for receiving working electrode I 1 and working electrode II is gone forward side by side row relax and export the computer system 7 of comparing result and provide the power circuit 8 of power supply for electrode system; Certainly, computer system planted agent installs specific software for calculation, or, directly adopt voltage response curve as the normative reference of gas penetration potential, also can realize goal of the invention; Meanwhile, computer system 7 can control power circuit 8, completes the whole course of work.
What finally illustrate is, above embodiment is only in order to illustrate technical scheme of the present invention and unrestricted, although with reference to preferred embodiment to invention has been detailed description, those of ordinary skill in the art is to be understood that, can modify to technical scheme of the present invention or equivalent replacement, and not departing from aim and the scope of technical solution of the present invention, it all should be encompassed in the middle of right of the present invention.